Satellite Images of Clouds over Thailand

How to read the cloud image

Cloud image colours

• Thin cloudThin mid- to high-level cloud, mostly without rain
• Thick cloudThicker cloud with colder tops; some rain possible
• High topsVery high, very cold tops, often the upper part of rain clouds
• ThunderstormCore of thunderstorm clouds; heavy rain possible
• SevereTops of very severe thunderstorms

The image is coloured by cloud-top temperature: the higher the cloud top, the colder it is. Transparent areas have no cloud, or only low clouds whose tops are almost as warm as the ground. Faint to solid white is mid- to high-level cloud, blue is very high and very cold cloud that is often the top of rain clouds, yellow to orange is the core of thunderstorm clouds, and red to magenta marks cloud tops that have shot up very high, usually in severe thunderstorms.

Cloud does not always mean rain. Some white cloud is thin high cloud that brings no rain, while yellow, orange or red clusters are more likely to bring heavy rain. The rain that actually reaches the ground can be more or less than the colours suggest, so the image tells you where clouds are worth watching, not how many millimetres fell.

An infrared image only sees the heat of whatever is on top. Low clouds with warm tops, fog, or rain from shallow clouds may not appear at all, so some provinces get rain while the image looks clear. The reverse also happens: a wide sheet of white high cloud may have no rain beneath it.

A good way to use it is to play the animation on the map to see which way the clouds are moving, then compare with the measured rain table on this page, or turn on the rain layer to see rain gauges on top of the clouds. If orange or red clusters sit over a region where the table shows heavy rain, rain there may continue. If clouds are moving towards you, check the water level at a station near you as well.

Each image has its time shown under the map in Thailand time. The latest image is a little behind real time because it needs processing before release. If the latest image is too old, this page says there is no recent image instead of showing an old one.

The timeline under the map continues past the real images with a forecast part covering about the next 12 hours, showing the cloud expected hour by hour. It is the same kind of picture as the real cloud images and uses the same colours: white is cloud, blue is high cloud tops, and yellow, orange and red are thunderstorm clouds expected to develop. This part uses a different bar colour from the real images and is marked "Forecast" next to the time. Forecast frames look smoother than the real images because they are a broad estimate, not a photograph. The place and timing of real clouds may differ, and this layer does not show rainfall amounts, so use it for the trend together with the latest real cloud image and the measured rain.

How cloud images differ from rain radar

This site does not show weather radar. The images here come from a satellite looking down from space at cloud tops, while a weather radar stands on the ground and bounces signals off raindrops in the air. Radar therefore shows the position and strength of falling rain more closely, but only within range of each radar station.

A satellite sees clouds across the whole country and the surrounding seas, which suits the big picture, such as a monsoon trough or an approaching storm. To know how much rain actually fell, look at measured rain from rain gauges, which record the rain that reaches the ground.

Rain today nationwide · Dam water levels · Water levels nationwide